Starting system for internal-combustion turbine power plants



Sept. 9, 1952 N. c. PRICE 2,609,

STARTING SYSTEM FOR INTERNAL-COMBUSTION TURBINE POWER PLANTS Original Filed June 2, 1945 5 Sheets-Sheet 1 iii I I I H? L L z Hg l' i l H g: 1 i MEL i=:: i I 5'- HH 1 E i 6.? ff 1' 5 i E 5: I i i; i a H I. I I

i I i i :5 1 V I I Q I I87 v "a 7 i 88 I48 ii I4T/ I52 I53 I54 I64 I INVENTOR. 16 0:0 NATHAN 0. PRICE 23 9 I62 23 233 2 234 Agent Sept. 9, 1952 N. c. PRICE 2,609,659

STARTING SYSTEM FOR INTERNAL-COMBUSTION TURBINE POWER PLANTS Original Filed June 2, 1945 5 Sheets-Sheet 2 1- 1 8 6 g 5 a m j i 03 ml 1 5 ow; m i 8 q- I: 0 Kg 00 N g I'D E o0 8 m m m 8 g o w r w N 8 8 '5 93 5 i v a. I A {3| IL m 1 Q Q .:3 3 INVENTOR. 5 j BY NATHAN 6. PRICE Agen t N. c. PRICE 2,609,659

ION TURBINE POWER PLANTS Sept. 9, 1952 STARTING SYSTEM FOR INTERNAL-CGMBUST 5 Sheeigs-Sheet 3 Original Filed June 2, 1945 mm vw mm Ilu...

INVENTOR. NATHAN 0. PRICE m m H 4 1 QQ w I N. C. PRICE Sept. 9, i952 STARTING SYSTEM FOR INTERNAL-COMBUSTION TURBINE POWER PLANTS 5 Sheets-Sheet 4 Original Filed June 2, 1945 IINVENTOR. NATHAN 0. PRICE A'gent N. C. PRICE Spt. 9, 1952 STARTING SYSTEM FOR 'INTERNALCOMBUSTION TURBINE POWER mms Original Filed June 2, 1945 5 Sheets-Sheet 5 INVENTOR.

- NATHAN C. PRICE Patented Sept. 9, 1952 STARTING SYSTEM FOR INTERNAL-COM- BUSTION TURBINE POWER PLANTS Nathan C. Price, St. Helena, Calif., assignor to Lockheed Aircraft Corporation, Burbank, Calif.

Original application June 2, 1945, Serial No. 597,308. -Divided and this application March 24, 1948, Serial No. 16,856

16 Claims.

This invention relates to internal combustion gas turbinesand relates more particularly to a starting means and associated controls for such powerplants. It is a general object of this invention to provide a reliable inexpensive starting system for incorporation in turbo power plants designed for a Wide range of applications.

The present application is a division of my pending application serial No. 597,308 filed June 2, 1945.

The starting system of this invention is adapted primarily for embodiment in a self-contained gas turbine power plant having its own fuel pump system, electric generator, lubricant pump, etc. and it is another object of the invention to provide astartingsystem for this class of power plants that is coordinated with the various elements of the plant to obtain a rapid sure starting of the powerplant and the proper automatic control of the air and fuel injection and electric generating instrumentalities.

Another object of the invention is to provide a starting system which utilizes the air compressor and fuel pump of the fuel injecting system to supply air and fuel under pressure to an accumulator tank and which incorporates an automatic sequence control for governing the ignition and delivery of the air and fuel mixture from said tank to a starting nozzle which directs a stream of starting gases against the blading of an air compressing element of the power plant. The starting system embodies a motor generator whichis energized by battery current to initially drive the air compressor of the fuel injecting system to supply compressed air to the accumulator tank of the starting system. The motor generator also serves as a motor to initially drive the lubricant pump and fuel pump to pre-lubricate the various elements of the power plant and to build up fuel pressure for operation of the plant. The sequence control of the starting system provides forthe correctly related or timed operation of the starting valve, the diversion of the air and fuel'pressure to the injector, and the energization of the fuel igniting glow plug to initiate operation of the power plant.

A further object of the invention is to provide a power plant structure of the character described in which the starter motor and auxiliary generator, the fuel and oil pumps, the air injecting blower andother accessories are incorporated in a compact assembly removably secured to the housing of the power plantfor convenient installation, servicing and replacement...

Other objectives and advantages of the invenz 7 tion will become apparent from the following detailed description of a typical preferred embodiment wherein:

Figure 1 is a side elevation of a power plant embodyingthe present invention arranged in a tubular shroud showing the shroud in longitudinal cross section;

Figure 2 is an enlarged, vertical sectional view of the auxiliary assembly of the power plant;

Figure 3 is an enlarged, longitudinal detailed sectional viewof the forward and major portion of the power plant;

Figure 4 is a longitudinal, sectional view of the various circuits of the powerplant' and starting system. I e ,7

The internal combustion turbo powerplant illustrated in the drawings and which incorporates the features of the invention comprises, generally, compressor means Ill, a heat exchanger I I receiving the compressed air from the com-' pressor ID, a combustion chamber l2, turbine means I3, driving propeller blading B, a fuel supply system' [6 and astartin'g means ll.

In Figure 1', the power plant is illustratedarranged in a tubular shroud or envelope S. The rear portion of the shrouds is rearwardly, convergent for the'discharge of the air stream from the blading .B, and the airand gases of combustion generated by the powerplant, to obtain a reaction propulsive efiect. However, the primary propulsive efiect is obtained by the in-tube blading B. The housing assembly of the power plant includes a tubular intermediate section-2| having a tapered forward portion. A front section 22 is I secured to the forward end, of the 's'ection;2l and a separately formed cylindrical member 24. is seecured within the intermediate section z l A third tubular housing section 28 is securedto the rear end of the intermediate section 2| and an elongate tubular shell 3| ,extends rearwardly from the section 28 touenclose the heat exchanger l l.

Spaced lugs 32 project from the intermediate section 2| and supporting arms 33-are secured to the lugs. The arms 33 are fixed to the shroud S to support the power plan concentrically within the shroud.

The compressor means it has a series of spaced air inlet passages 35 extending inwardly and rearwardly through the intermediate section 2i and member 24. The passages 35 diminish rearwardly in capacity to an annular chamber 31. The power plant includes a central rotor R and a counterrotating ring 69 surrounding the rotor. The rotor R, which carries both. compressor and turbine blading, is provided at its rear end with the combustion chamber i2 is circular while the an axle 42 supported by a bearing 43 carried in I a journal box 5| on a central web 48, see Figure 6. The web 48 projects upwardly from a member l at the rear of the housing section 28. A shaft 5 1 is secured in the forward opening in the rotor R and is journaled in a boss 39 on an upwardly extending web 38 of the member 24, see Figure 5.

The abovementioned compression chamber 3?, which is annular, extends rearwardly from the inlet passages 35 and then curves radially outward. The rotor R. has an intermediate portion of increased external diameter and the forward face of this portion forms one Wall of the outwardly extending part of the chamber 37. The chamber 37 decreases in capacity in the direction of air flow and compressor vanes 51 are provided on the rotor R. for operation in the chamber. The counter-rotating ring Bil carries diffuser blades 58 in an annular passage 6! leading radially through the ring from the exit of'the compressor chamber 37 to the periphery of the ring. A passage 6| is venturi shaped having a convergent entrance and a divergent "or flaring exit. The aforementioned casing section 28 has spaced curved walls 62 and 63 defining an air discharge passage 54 for the compressor. The passage 6 4 curves radially and rearwardly from the passage 5| of the ring and contains a series of spaced stationary diffuser vanes 59 pitched in the opposite direction to the rotating diffuser vanes 58. Seals 66 and 67 are provided between the rotor R and the counter-rotating ring 66 at opposite sides of the passage BI and bearing means 13 is provided for the ring 50. y

The air under pressure supplied by the compressor means l0 passes through the heat exchanger before it is delivered to the combustion chamber l2. The abovementioned shell 3i forms the outer wall of the heat exchanger ii and is provided at its rear end with an inturned lip 78 which engages with a tubular discharge fitting IS. The fitting l9 in turn cooperates with a shroud or faring 80 extending .rearwardly from the shell 3!. A tubular partition 8! of heat resistant metal is spaced within the shell lit to leave an annular passage 82 which extends rearwardly from the compressor discharge passage 54. The heat exchanger ll further includes an annular bundle or group of spaced tubes 84 arranged axially within the partition ill. The forward ends of'the tubes'il l are secured in openings in a partitionplate 85 arranged at the rear of the wall 53. The rear portions of the tubes 84 curve inwardly and are engaged in radial openings'in the rear portion of the partition 8 l Air under pressure from the compressor iii flows rearwardly from the annular passage 82 and enters the rear ends of the tubes 84 to flow for-' and air flowing from the turbine and the. com-,

pressed air so that the compressed air is prev iorward portion of the chamber is of diminishing capacity and curves radially inward to a restricted throat. Protective shrouds 88 and 98 are arranged in spaced adjacent relation to the walls 53 and 853 respectively, to leave cooling air spaces. A substantially annular shroud 388 is anchored to the web it and is arranged in the rear portion of the chamber l 2' substantially mid-way between 1e shrouds 88 and Gil. Hollow ring sections 93 and at are housed within the shroud 350 and ports of the turbine.

the fitting 79.

95 and 96 in the web 48 conduct fuel and air under pressure to th rings 93 and 94 respectively. The walls of the ring l'have spaced air orifices 9T discharging through ports 3! in the shroud 3G0. The'walls of the ring 93 have angular fuel orifices 58 joining the air orifices 8'! in such a manner that the fuel and air mixture is discharged into the combustion chamber.

-The counter-rotating ring Si} is driven by a row of reaction type turbine blades I92. The blades its project axially from the rear face of the ring 53 to project into the constricted exit throat of the combustion chamber l2. The gases of combustion and the heatedair flow through the restricted exit of the combustion chamber at a high velocity and'the buckets Hi2 absorb only a small proportion of the energy of the gases and air in driving the ring E0; The buckets 1 U2 elimihat the necessity for providing a nozzle ring between the combustion chamber and the expansion zone of the turbine.

The turbine 13 includes a generally cylindrical portion I04 of the wall 85 arranged in spaced surrounding relation to the cylindrical rear portion of the rotor R'toprovide the expansion zone The forward end of the wall I84 is curved in substantially concentric relation to the curved rear face of the rotor enlargement to provide the curved direction changing entrance of the expansion zone. 'A row of Francis type blading M5 is provided on the rotor R to operate in the curved entrance and to be acted upon by the expanding gases entering the turbine. Spaced rows of impulse type buckets I66 are provided on the cylindrical portion of the rotor R and the wall IE5 carries rows of stator blades ml which stand between the rows of rotor'bl-ades I85 and its. A turbine discharge member H5 is associated with the web 4d and has a collector chamberill at the rear end of the turbine expansion zone. Curved ducts H8 extend through the member H5 from the collector chamber H! to the heat exchanger Hto discharge the turbine exhaust gases into the-heat exchanger for flow 'therethrough and to ultimately discharge from The powerplant includes a lubricating and cooling system for the bearings of the rotor, the speed reduction drive, etc. This lubricating systern form the'subjec-t of my co-pending application Serial No. 12,821 filed March 3, 1948, and its details-are not'essen'tial to a full understanding of the present invention. Accordingly, it will suffice to state tha-tthe lubricating system includes a lubricantpump .153 embodied in the auxiliary assembly toibe more fully described below. The

pump I53 supplies lubricant under pressure to a passage I69 in a radial shaft I50 to flow to'the bearings of the transmission, the rotor, etc.

A detailed description of the particular form of transmission illustrated for transmittin power from the rotor R to the blading B is not necessary to a complete understanding of the present invention and this mechanism will not be described in detail. However, in order to understand the manner in which the abovementioned shaft I50 is operatively related to the rotor R to effect a starting of the power plant, it will be necessary to briefiy describe the transmission. The transmission includes two aligned cross shafts I33 journaled in the housing sections 2| and 22. Gears I38 of substantial diameter are fixed on the shafts I33 and mesh with a pinion I31 formed on the rotor shaft 44. A tubular propeller shaft I39 is supported in bearings I40 and MI carried in the casing section 22 and a gear I42 of substantial diameter is formed on the rear end of the shaft. The gear I42 meshes with pinions I43 on the cross shafts to provide the second stage of speed reduction. The shaft I39 is suitably coupled with the blading B to drive the same.

The fuel injecting system, the lubricating system, the fuel supply system I6, and the governor system for the power plant are incorporated in an assembly removably secured to the power plant casing. In Figure .2 I have shown a flat surface boss I45 on the lower side of the casin section 22 to form a mounting for this assembly. The motor generator case I46 is engaged against the boss I45 to extend downwardly from the power plant and contains a motor generator 2'I3. The fuel supply system includes a blower I41 arranged at the lower side of the motor case I 46. The blower I41 is of the Roots type and comprises a housing formed of two end plates I48 separated by an intermediate margin plate I49. The abovementioned shaft I50 is the shaft of the motor, generator 2I3 and passes downwardly through the blower housing. A blower rotor I5I is fixed to the shaft I50 and the two lobed rotors I5I of the blower may be identical and are provided with the conventional meshing timing gears I52. The abovementionedpump I53 of the lubricating system is arranged below the blower I41. The pump of the fuel supply system is positioned below the lubricant pump I53 and includes a lower housing plate I63 and a scroll plate I64 arranged between the plate I63 and the lower plate I54 of the lubricant pump. Th rotor I65 of the fuel pump is fixed to the shaft I50 to operate within the scroll plate I64. Cap screws I62 pass through openings in the motor generator case I46 and through aligned openings in the several plates of the blower I41, lubricant pump I53 and fuel pump. The upper ends of the screws I62 thread into openings in the boss I45 to secure the assembly to the power plant casing.

An oil sump I16 is arranged below the power plant at the rear of the auxiliary assembly just described. The pump I16 receives the hot lubricant and cooling medium leaving the power plant and contains a quantity of the liquid medium for re-circulation through the power plant. A block I80 bears upwardly against the abovementioned web 40 and the upper side of the sump I16 engages the block. 'An internal web I18 is provided in the sump and screws I8I pass through vertical openings in the sump I16, web I18 and I41 described above.

6 7 block I and thread into openings in the web 49 to secure the sump to the power plant.

The fuel supply system I6 includes the blower It is preferred to bleed compressed air from the compressor means I0 of the power plant to the inlet side of the blower I41 so that a double stage of compression is obtainedfor the injection air supplied to the ring 94 of the fuel injecting manifold. A duct I81 extends from the outlet passage 64 or 82 of the compressor means I0 and passes through the Web I18 of the sump to the inlet of the blower I41. The air passing through that portion of theduct I81, which is in the web I18, is in heat absorbing or heat transfer relation to the heated oil of the sump whereby the air is heated during its passage to the blower. A duct I88 returns back through the web I18 of the sump to the block I80 so that the compressed air is again heated before delivery to the manifold ring 94. A shuttle valve I90 is interposed between the duct I88 and the abovementioned passage 96, which finally conducts the air to the injection ring 94. The valve I90 as shown in Figure '7 is a cylindrical part slidably arranged in a horizontal opening in the block I80. An annular external groove I9I is provided in the valve I90 and in the open position of the valve, communicates with the two passages I88 and 96to connect the same. It will be seenthat during operation of the power plant thefuel injecting air is compressed by the compressor mean I0, is preheated during its passage to the blower I41, is compressed by the blower I41, and is again heated before delivery to the manifold injecting ring 94.

A fuel supply line I92 leads from a suitable fuel supply, not shown, to the intake of the fuel pump and a duct I93 extends from the high pressure side of the pump through the sump web I18 and the 'block I80 to the valve I90. The fuel absorbs heat during its passage through that portion of the duct I 93 which extends through the web I18. The valve I90 is interposed between the duct I93 extending from the fuel pump and theabove referred to'passage which conveys the fuel under pressure t the injecting ring 93. The valve I90 is provided with an external annular groove I94, which communicates with the duct I93 and the passage 95 to allow the free flow of the fuel to the injecting ring 93 when the valve is in its open position.

The starting means I1 isoperable to prelubricate the various. power plant bearings, raise the fuel pressure, and spout or jet a stream of combustion gases against the buckets I02 of the counter-rotating ring 60 to drive the ring and thus develop sufiicient air pressure in the plant for starting. The sequence control, to be later described, provides for the diversion of fuel and air pressure to the injecting rings 93 and 94 for the starting and for continued power plant operation. The starting means includes a tank I95 positioned within the inner wall I20 of the heat exchanger II; see Figure 4. The tank I95 may be attached to .the web 40 and extends rearwardly therefrom in spaced relation to the wall I20 of the heat exchanger I I to leave an annular cooling air passage I22. The rear end of the tank may be provided with a faired or rearwardly convergent 'cap I96. A single passage I91 extend through the web 40 and block I80 from the interior of the tank I95 to the valve I90, as shown schematically in Figure 7. A second passage or duct I98 is provided to extend from the valve to a nozzle'l99'formed and arranged to spout against the buckets I02 of the counter-rotating ring 60. The nozzle I99 is of the De Laval type, and projects forwardly from the wall 89. As illustrated in Figure 7, an end portion of the valve I 98 controls communication between the passages I91 and I98. The valve I9!) is biased by a spring 252 to the closed position illustrated in Figure '7 where it closes ofi communication between the passages I91 and I98.

The starting means I! provides for the deivery of compressed air and fuel to the starting tank IQE and for the ignition of the fuel and air mixture therein t create a substantial volume of combustion gases under pressure which are discharged from the nozzle I9 9 to initiate turbine operation. A branch passage 200 in the Web 40 extends from the air pressure passage I88 to the tank passage IQ'I. This branch passage is controlled by the valve I90, the valve having 2. diametric port 2M which completes the passage 286 when the valve is in the position of Figure 7, the passage 26!} being closed when the valve is in its normal open position. The fuel passage I93 has a branch 263 extending to the valve I913 where it communicates with an annular external groove 292 when the valve is in the position illustrated in Figure 7. An axial port 203 extends through the valve I98 from the groove 202 to the abovementioned diametric air pressure port 20L This arrangement provides for the delivery of the fuel t the air port 2M, and the air passing through that port shears on the fuel stream to break up the fuel and assure the delivery of an effective fuel and air mixture to the starting tank I85.

The starting means I? further includes an ignition system for igniting the fuel and air mixture in the tank 595. A glow plug or igniting plug 204 is arranged in the block I80 to have its resistance glow wire exposed in the starter tank passage I97. The plug gt linthis location is readily accessible and is not subjected to the high temperatures generated in the combustion chamber. A lead 265 extends from one terminal of the plug 204 to a storage battery 206, and a lead 207 extends from the other terminal of the plug to a pressure sensitive switch, 2138. switch 283 may be of the diaphragm or bellows type, and its pressure chamber has communication with the duct I81 leading from the discharge passage 64 of the compressor means It]. Figure 7 diagrammatically illustrates a branch line 269 extending from the duct I 81 to the pressure operated switch to subject the same to the pressure in the passage 64 of the compressor means Ill. The switch embodies a movable contactor controlled by the pressure sensitive bellows and two spaced stationary contacts 2&9 and 2H engaged by the contactor in its two positions. The lead 281 from the ignition plug 284 connects with the contact 2 I B, and the contactor remains in engagement with this contact until a predetermined pressure is built up by the compressor means It. A conductor 2I2 extends from the contactor of the pressure responsive switch 2&8 to a master switch H3, and thence to the battery 286. When the master switch M3 is closed, a circuit is completed to the ignition plug 204 through the leads 295 and 267 the pressure switch 208 and the lead 2I2. The ignition plug 204 is designed to ignite the rich fuel and air mixture in the tank I95 a predetermined time subsequent to closing of the master switch 2 I3. For example, the plug 284 may be constructed to cause ignition of the The pressure operated mixture ten or twelve seconds after closing of the master switch.

Provision is made for automatically shifting the valve I98 from the position of Figure 7 to the open position upon igniting the fuel and air mixture in the starting tank I95. The valve I98 is stepped or graduated in diameter to have an axially facing annular piston surface or shoulder 264. The starter tank passage IE1 or the end portion of the passage i9? communicating therewith, has a branch port 265 for delivering pressure to the piston shoulder 26d of the valve. The above described spring 262 initially holds the valve I96 in the position of Figure 7 where the passage I98 is closed. Upon igniting of the fuel and air mixture in the starting tank I95 and its passage I91, the resultant pressure is conveyed through the port 265 to act against the shoulder 264, and the pressure thus applied suddenly reverses the valve I99. When the valve I 99 is thus reversed, the gases of combustion are free to flow through the passage I98 to the nozzle I99 and the passages 95 and 95 of the fuel injecting system are opened to receive the air and fuel under pressure for power plant operation. The shifting or reversal of the valve I also closes the starting fuel and air passages 263 and 200.

Releasable means is provided to hold the valve I98 in the open position where fuel and air under pressure are delivered to the injecting rings 93 and 92. This means may comprise a spring urged detent 285 for cooperating with a notch 251 in the valve I96, When the valve I9!) is moved to the open position by the gas pressure acting upon its shoulder 265, the detent 266 snaps into the notch 26?. The engagement of the detent 268 in the notch 28? assisted by the pressure in the combustion chamber I 2 acting upon the reduced end of the valve I98 and conveyed thereto by the nozzle I99 and the passages I93 and 265, holds the valve in the open position. The combined efiect of the detent 266 and the combustion chamber pressure acting on the valve 90 overcomes the spring 262. However, when the pressure in the combustion chamber falls to a given value at the termination of power plant operation, the spring 262 overcomes the detent 25S and restores the valve 19s to the position of Figure 7 and thus conditions the power plant for restarting. From this it will be seen that the shuttle valve I99 and the associated parts are governed by. the pressures generated in the starting tank I and the combustion chamber 52 to provide for the power plant starting and stopping sequence.

The motor-generator 2I3 housed in the abovementioned case It'd serves to drive the blower I47, the lubricant pump 53 and the fuel pump, during the starting cycle, to pro-lubricate the several bearings of the power plant and to supply the mixture of fuel and air under pressure to the starting tank'l95. The motor-generator, as diagrammatically illustrated in Figure '7 of the drawings, includes a series field coil 2M and a shunt field coil THE. A conductor 2I'I extends from the abovementioned lead 2 2 to terminals of the coils 2M and 2E5 and thence to the solenoid 2I8 of a voltage regulator 2Il associated with the generator. A shunt or cut-out line 268 connects the series field coil 21s with the contact 2 of the pressure controlswitch 268 so that the coil is shorted out when idling speed ofthe power plant is approached or attained. The shunt field coil 2I5 has one terminal connected to a carbon pile 220 and a tap 22I connects the other end of the carbon pile and one side of the solenoid 2 I8 with the battery lead 205, the other side of the solenoid being connected in the line 2 IT. The carbon pile 220 is varied or controlled by a spring urged plunger 22I, and the latter is adapted to be acted upon by the solenoid 2I8.'

It will be seen that the motor-generator H3 is circuited to serve as a motor when the contactor of the pressure-sensitive switch 208 is in engagement with the contact 2I0 and is circuited to serve as a generator when the contactor of switch 208 is in engagement with the contact 21 I.

A releasable or overrunning drive is provided between the motor-generator 2I3 and the transmission of the power plant rotor R so that the motor-generator is driven by the power plant to operate as a generator during power plant operation. The overrunning drive includes a pinion 2'22 freely rotatable on the stationary trunnion I12 and meshing with the gear I42; see Figure 2. The pinion 222 is supported by the trunnion and a bearing 223 carried by. the abovementioned boss I45 of the power plant case. The shaft I50 of the motor generator has its upper end portions supported by a bearing 224 in the case I46, and a plug 225 is arranged in the lower end of the pinion 222 to oppose the end of the shaft. The opposing ends of the shaft I50 and plug 225have cooperable clutch teeth 226. Spiral splines 22'! are provided on the plug 225 and the interior of the pinion 222, and cooperate to feed the plug downwardly and thus engage the clutch teeth 226 when the pinion 222 is driven by the power plant to rotate with respect to the shaft I50 of the motor-generator. Thus when the power plant is in operation the motorgenerator is driven to supply current to the battery circuit. When the motor-generator is operating as a motor, the clutch teeth force the plug 225 upwardly to disengage the teeth.

Provision is made for manual operation of the blower I41, oil pump I53 and fuel pump for the purpose of starting the power plant in the event the battery 206 is dead or weak. This means includes a conveniently located hand crank 230 for driving a flexible cable 23l through the medium of a gear train 232. The cable 23I extends to the lower end of the shaft I50 where it is provided with a socket member 233. As illustrated in Figure 2, the socket member is rotatably supported in a bearing cap 234 and is sealed about in the lower plate I63. A plug 235 is arranged in the socket member, and the member and plug have cooperating spiral splines 236 operable to produce axial movement of the plug. The opposing ends of the shaft I50 and plug 235 have overrunning clutch teeth 231. The teeth 231 and the spiral splines 235 are constructed and related so that during rotation of the shaft I50 by the power plant, or by the motor-generator '2I3, the teeth 23! are disengaged. However, when the member 233 is rotated by operation of the hand crank 230, the splines 236 feed the teeth of the plug 235 into engagement with the teeth of the shaft I50 so that the blower M1, the fuel pump and the lubricant pump I53 are manually operated, through the drive just described, to condition the power plant for starting. It is to be understood that the manual starting 'means just described is primarily an emergency device to be employed when the battery is dead.

The speed governing means l8 of the inven-' tion provides for substantially constant operating speed of the power plant at any one of a plurality of selected manual settings of a manual throttle or control lever 240.

The discharge pressure characteristic of the lubricant pump or- 10 the fuel pump is utilized as the control factor of the speed governing means. In the preferred arrangement"illustrated, the discharge pressure characteristic of the fuel pump is employed as the speed governing factor. The fuel pump when employedin this manner, has a centrifugal impeller I65 provided'with vanes which lean forwardly relative to its direction of rotation. A speed governing valve or throttle valve MI is interposed in the discharge passage I93 leading from the fuelpump. This valve is a discharge pressure operated, manually settable valve, including a piston 242 operating in a cylinder having a'branch port-243 which carries the discharge pressure of the fuel pump to act upon the piston. A needle or stem 244 on the piston 242 cooperates with a seat or angular portion of the fuel passage I93 to control'the flow of fuel to the injecting means. A lever 246 is operated by the abovementioned'throttle lever 240 through the medium of a suitable linkage 241 and a compression spring "248 is arranged betwen an arm ofthe lever 246 and the rear side of the piston 24:2; When a fuel pump of the character above described is employed it has a slightly rising pressure characteristic with an increase in flow, but .thepump curve is substantially fiat. The fuel pump discharge pressure varies substantially in accordance with the square of the turbine speed, regardless of the fuel flow rate change accompanying" altitude variations. Therefore, when the throttle lever 240 is set to a given P t t 5 of full speed forexample, the spring pressure againstjthe discharge pressure operated piston is adjusted to obtain a substantially constant speed which is practically unaffected by altitude variations, propeller loadin and other external conditions. However, the speed will increase slightly with an increase in altitude of the aircraft. The output of'the fuel pump and the air pressure conditions in the combustion chamber of the power plant are related so that the fuel flow does not exceed a value where the substantially; flat curve characteristics of the pump no longer prevail. As illustrated in Figure '7 of the drawingSJ he throttle lever 240 may have several predetermined and calibrated settingssuch as off, idle, 50% R. P. M. and R. P. M. When the throttle lever 240 is in the off position, the stem 244- completely closes the fuel duct I03, and when the lever is in the start or idle position, the valve is cracked or only slightly opened to allow the delivery of fuel sufficient for starting and idling of the power plant. a a V The abovementioned master switch M3 is preferably associated with the manual throttle so that only a single manual operating member is required to start, stop and control the power plant. In Figure? Ihave shown a lever 210 connected to the linkage 241' for operating the master switch M3. The arrangement is such that-the switch 4| 3 is open when the lever 240 is in the-off position; and closed when the lever is in the other positions.

A drain 215 communicates with the combustion chamber II and extends to the atmosphere to carry away excessivefuel in the event the combustion chamber II becomes flooded during startingof the power plant.

Operation To start the powerplant, the control or throttle lever 240 is movedto the start or idle position. This closes the master switch 4| 3 to energize the motor generator 2 I3 and tdsupply current to the igniting plug 204. The motor generator energized by the battery 206 drives the blower I41 to supply air under pressurev to the starting tank I95, drives the fuel pump to raise the fuel pressure and supply fuel to the starter tank I95, and drives the lubricant pump I53 to raise the lubricant pressure and pre-lubricate the various power plant bearings. At this time the valve I90 is in the position of Figure '7, and the air pressure flows through the branch duct 200 and the port 20I to thestarting tank and fuel is'supplied through the branch passage 263 and the valve port 203 to the starter tank. At the end of a predetermined limited period established by the design or setting of the glow plug 204, the plug ignites the rich fuel and air mixture in the starter tank I95. Ignition of the fuel and air mixture results in the generation of sufiicient pressure in the tank and the passages I91 and 265 to drive the valve I90 to its open position against the action of the spring 202. The starter valve I90 is subsequently re-'- tained in the open position by the detent 260 and by the combustion chamber pressures acting on its exposed end as above described. Opening of the starter valve I90 allows the combustion gases under'pres'sure to flow from the starter tank I 95 through the passage I98 to spout from the nozzle I99. The gases thus discharged by the nozzle I99 impinge against the buckets I02 of the counter-rotating ring 60 to spin the ring.

Opening of the starter valve I 90 also diverts the air pressure from the blower I4I to the injection ring 94 and diverts the fuel under pressure from the fuel pump to the ring 93. The fuel and air mixture thus introduced into the combustion chamber I2 ignites in the chamber. The plant accelerates to idling speed by reason of the combustion gases from the chamber I2 driving the turbine I3, which, in turn, drives the compressor means I0. Op'eratidn of the compressor means I increases the air pressure at the discharge passage 64 of the compressor. When the pressure in the passage 54 reaches a given value, the contactor of the pressure sensitiveswitch 200 moves from'the contact 2I0 to the contact 2II to de-eriergize the glow plug 204 and to disconn'ectthe motor-generator 2I3 from the battery 206. When the pinion 225 is driven by the power plant relative to the motor-generator shaft I50, the overrunning clutch teeth 225 engage so that the motor-generator is driven by the power plant to supply current to the battery circuitunder the control of the voltage regulator 2I9. When the throttle or control lever 240 is moved to a position to put the power plant on a power producing basis, the motor-generator becomes an effective electrical generator.

It is tobe particularly noted that the starting sequence is automatic, and for normal starting it is only necessary to move the lever 240 to the starting position. In the event the power plant fails to start, the lever 240 may be restored to the ofi position and then again moved to the starting position where the above described operations arerepeated. Having described only atypical form of the invention, I do not Wish to be limited to the specific details herein set forth, but wish to reserve to myself any variations or modifications that may appear to those skilled in the art and fall within the scope of the following claims.

I claim:

1. In an internal combustion gas turbine, an

expansion zone; a combustion chamber for supplying gases of combustion to the expansion zone, a compressor casing, a rotor, turbine blading on the rotor operating in the expansion zone, compressor blading on the rotor operating in said casing, a counter-rotating ring having diffuser blading in surrounding relation to said compressor blading, means for conducting the compressed air from the difiuser blading to the combustion chamber, buckets on the ring positioned to be acted upon by the gases of combustion' entering the" expansion zone to rotate the ring, and starting means including a nozzle for spouting fluid under pressure against said buckets.

2. In an internal combustion gas turbine, an expansion zone, a combustion chamber for supplying gases of combustion to the expansion zone, a compressor casing, a rotor, turbine blading on the iotor'operating in the expansion zone, compressor blading on the rotor operating in said casing, a; counter-rotating ring having diiiuser blading in surrounding relation to said compr essor blading, means for conducting the compressed air from the diffuser blading to the combustion chamber, buckets on the ring positioned to be acted upon by the gases of combustion entering the expansion zone to rotate the ring, and means for starting the turbine plant including a container for an explosive mixture, means for igniting said mixture, and nozzle means for jetting the resultant combustion gases against the buckets of the ring to rotate the ring.

3. In an internal combustion gas turbine power plant, turbine means having a rotor and series of blading, a combustion chamber discharging gases of combustion under pressure into the turbine means, means for injecting fuel and air under pressure into the combustion chamber for power plant operation including a fuel pump and an air pump, and means for starting the power plant comprising a container, means for operating said pumps to supply a mixture of fuel and air under pressure to said container, means for igniting said mixture, and nozzle means for jetting the gases of combustion, resulting from the igniting of said mixture; against certain of said blading.

4. In an internal combustion gas turbine power plant, turbine means having a rotor and series of blading, a combustion chamber discharging gases of combustion under pressure into the turbine means, means for injecting fuel and air under pressure into the combustion chamber for power plant operation including a fuel pump and an air pump, and'meansv for starting the power plant comprising'a container, means for operating said pumps to'supply a mixture of fuel and air under pressure to said container, there being a passage leading from said container, a glow plug in said passage for igniting said mixture in the container, and nozzle means for jetting the gases of combustion, resulting from the igniting of said mixture, against certain of said blading.

5. In an internal combustion gas turbine power plant, turbine means having a rotor and series of lading, a combustion chamber discharging gases of combustionunder pressure into the turbine means, fuelinjecti'ng means in the combustion chamber, fuel and air pumps for supplying fuel and air under pressure to the injecting means, a drive between the rotor and pumps operative only during power plant operation, and means for starting the'power plant comprising a container, ducts leading from said pumps to the container, means for operating the pumps to supply fuel and air under pressure to the container through said ducts, means for igniting said mixture in the tank, and nozzle means for discharging the gases, resulting from the igniting of the fuel and air mixture in said container, against certain of said blading.

6. In an internal combustion gas turbine power plant, turbine means having a rotor and series of blading, a combustion chamber discharging gases of combustion under pressure into the turbine means, fuel injecting means in the combustion chamber, fuel and air pumps for supplying fuel and air under pressure to the injecting means, a drive between the rotor and pumps operative only during power plant operation, and means for starting the power plant comprising a container, ducts leading from said pumps to the container, means for operating the pumpsto supply fuel and air under pressure to the container through said ducts, means for igniting said mixture in the container, and nozzle means for discharging the gases, resulting from the igniting of the fuel and air mixture in said container, against certain of said blading, and valve means for diverting the fuel and air under pressure from said ducts to said injecting means subsequent to the igniting of said mixture.

'7. In an internal combustion gas turbine power plant, turbine means having a rotor and series of blading, a combustion chamber discharging gases of combustion under pressure into the turbine means, fuel injecting means in the combustion chamber, fuel and air pumps for supplying fuel and air under pressure to the injecting means, a

drive between the rotor and pumps operative only during power plant operation, and means for starting the power plant comprising a container, ducts leading from said pumps to the container, manually operable means for operating the pumps to supply fuel and air under pressure to the container through said ducts, means for igniting said mixture in the tank, and nozzle means for discharging the gases, resulting from the igniting of the fuel and air mixture in said container, against certain of said blading.

8. In an internal combustion gas turbine power plant, turbine means having a rotor and series of blading, a combustion chamber discharging gases of combustion under pressure into the turbine means, fuel injecting means in the combustion chamber, fuel and air pumps for supplying fuel and air under pressure to the injecting means, a drive between the rotor and pumps operative only during power plant operation, and means for starting the power plant comprising a container, ducts leading from said pumps to the container, a motor-generator for operating the pumps to supply fuel and air under pressure to the container through said ducts, means for igniting said mixture in the tank, and nozzle means for discharging the gases, resulting from the igniting of the fuel and air mixture in said container, against certain of said blading.

9. In an internal combustion gas turbine power plant, turbine means having a rotor and series of blading, a combustion chamber discharging gases of combustion under pressure into the turbine means, fuel injecting means in the combustion chamber, a fuel pump for pumping fuel under pressure to said injecting means, a motor-generator associated with the pump and operable as a motor to drive the pump to prime the plant for starting, an overrunning drive between the rotor and the motor-generator for driving the latter as a generator during power plant operation, and means responsive to the pressure developed by said compressor means for. c'ircuiting the motor-generator as a generator. P

10. In an internal combustion gas turbine power plant, turbine means having a rotor and series of blading, a combustion chamber discharging gases of combustion under pressure into the turbine means, fuel injecting means in the combustion chamber, a fuel pump for pumping fuel to the injecting means, means operable by the igniting or" a fuel charge for starting the power plant, a motor-generator connected with the pump and operable as a motor to drive the pump for the pumping of said charge to the starting means, a battery circuit for energizing the motor-generator to drive the pump, means for circuiting the motor-generator as a generator for the battery circuit when the power plant goes into operation, and a drive between the rotor and the motor-generator operative during operation of the power plant.

11. In an internal combustion gas turbine power plant, turbine means having a rotor and series of blading, a combustion chamber discharging gases of combustion under pressure into the turbine means, compressor means for supplying air under pressure to the combustion chamber, fuel injecting means in the combustion chamber, a fuel pump for pumping fuel to the injecting means, means operable by the igniting of a fuel charge for starting the power plant, a motor-generator connected with the pump and operable as a motor to drive the pump, a valve initially diverting the fuel from the pump to the starting means and operable upon the igniting of said charge to direct the fuel from the pump to the injecting means, a battery circuit for energizing the motor-generator to drive the pump for the purpose of supplying said charge to the starting means, means responsive to the pressure generated by the compressor means for circuiting the motor-generator as a generator for the battery circuit, and an overrunning clutch drive between the rotor and motor-generator for driving the latter when the power plant goes into operation.

12. In an internal combustion turbine power plant, turbine means, compressor means, a combustion chamber, an annular heat exchanger receiving the discharge gases from the turbine and conducting compressed air from the compressor means to the combustion chamber, the annular heat exchanger defining an internal space, and means for starting the power plant including a tank within the space definedby the annular heat exchanger and means for supplying an explosive starting mixture to the tank.

13. In an internal combustion tubrine power plant, turbine means having blading, a normally operating combustion chamber for supplying combustion gases to the turbine means, a starting combustion chamber for supplying combustion gases under pressure to the blading to start the plant, and selective means for supplying fuel to said chambers, including means for conducting fuel to said chambers, and a transfer valve for controlling the last named means and responsive to pressures in said chambers.

14. In an internal combustion turbine power plant, turbine means having blading, a normally operating combustion chamber for supplying combustion gases to the turbine means, a starting combustion chamber for supplying combustion gases under pressure to the blading to start the plant, and selective means for supplying fuel to said chamber, including separate means for conducting fuel to said chambers, and a transfer '15 valve for controlling the last named means and responsive to pressures in said chambers.

15. In an internal combustion turbine power plant, turbine means having blading, a normally operating combustion chamber for supplying combustion gases to the turbine means, a starting combustion chamber for supplying combustion gases under pressure to the blading to start the plant, and selective means for supplying fuel to said chambers including separate means for conducting fuel to said chambers, a valve for controlling the last named means, means responsive to pressure in the starting chamber for operating the valve from the position where fuel is conducted to the starting chamber to the position where fuel is conducted to the normally operating chamber.

16. In an internal combustion turbine power plane, turbine means, compressor means oper ated by the turbine means, a combustion chamber interposed between the compressor means and the turbine means, and means for starting 16 the power plant comprising a starting combustion chamber for supplying combustion gases under pressure to the turbine means, a glow plug in the last named chamber, and means responsive to pressures developed by the compressor means for controlling the glow plug.

NATHAN C. PRICE.

REFEBENKIES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,388,707 Heinze Aug. 23, 1921 2,112,672 Lasley Mar. 29, 1938 2,257,982 Seippel Oct. '7, 1941 2,262,195 Noack Nov. 11, 1941 2,411,552 New Nov. 26, 1946 2,452,298 Geode Oct. 26, 1948 2,454,310 Ganahl Nov. 23, 1948. 

